Vat dyestuff and process of making same



Patented May 19, 1925.

UNITED STATES-1 PATENT OFFICE.

KARL'WILKE AND JosEr STOCK, or HOCHST-ON-THE-MAIN, GERMANY, ASSIGNORS TFARBWERKE vonm. nEIs'rER :LUcIUs & Baum-No, or HOCHST-ON-THE-MAIN,GERMANY, A CORPORATION or GERMANY.

VAT DYESTUFF AND PROCESS OF MAKING SAME.

' No Drawing.

'1 nitrogen-containing derivatives of dibenzanthronyls anddihenzanthrones which are produced by the action of nitrating means upondibenzanthronyls and also upon dibenznnthron'es, yield by a fusion withcaustic potash vat-dyestuffs specially interesting by 'virtue of theirshade Dibenzanthronyl and dibenzantln'one have most probably thefollowing formulae- W I ofi/g/ o as '(YW I I p l p A, i l v 0/ W y 40dibe nzanthronyl dibenzanthrone (See German Patent No. 407,838) (SeeGerman Patent No. 290,079).

Examples.

1. 40 parts of nitro-2.2-dibenzanthronyl are stirred at 160180 into amolten mixture 01' 400 parts of caustic potash and 200 parts of alcoholand the temperature of the fusion is slowly raised to 225-230f. I Thestirring being continued for some t me at the same temperature, thefusion s dissolved m Application filed April 16, 1924. Serial No.706,988.

water, blown out 'with air for the urposeof oxidation of leuco compoundormed, acidified with hydrochlori acid, filtered and the solid mass iswashed. The dyestuif thus obtained forms a black paste. From the dark,claret-read alkaline hydrosulphite vat cotton is dyed greyish-blue toblack shades.

2. 15 parts of monoitrodibenzanthrone,

The dyestufl' is obtained in the form of a paste of a bluish-black colordyeing cotton from a violet alkaline hydrosulphite vat greyish-blue toblack tints of very good i'astness properties. w

3. A similar product is obtained if dinitrodibenzanthrone-obtainable bynitration of dibenzanthrone with concentratednitric acid in nitrobenzcneand forming a bluishgreen powder, soluble in concentrated sulphuric acidwith a brownish-violet color and with a content of nitrogen of 5.16%,-is subjected to a fusion, with alkali and worked up in the same way asindicated in Example 2).

I-[aving' now described our invention, what we claim is: 1

1. A process for the preparation of vatdyestuffs which consists intreating the nitrogen-containing bodies, obtainable by the action ofnitrating agents upon such products as are formed by condensing 2molecules of benzanthrone, with alkaline con densation means.

2. A rocess for the preparation of a vat dyestufi which consists innitrating 2.2- dibenzanthronyl and melting the product so obtained withcaustic alkali.

3. As new products the vdyestuffs which may be obtained by treating thebodies producedby the action of nitrating means upon such products asare obtained by condensing 2 molecules of benzanthrone, with alkalinecondensation means, which products form when. dry, dark colored powdersdissolving in concentrated sulphuric acid with a characteristiccoloration and dyeing cotton from green to grey and black shades of verygood fastness properties. i

4. As a new product, the vat dyestufi: obtainable by melting nitrated2.2-dibenzan thronyl with caustic alkali, being a black powder, solublein concentrated sulfuric acid with a. violet color, giving a claret,-

red vat with alkali hydrosulfite from which cotton is dyed greyish-blueto black shades. Y 10 In testimony whereof,we afiix our signatures.

KARL WJLKE. JOSEF STOCK. I

Witnesses:

HlLDE SCHIEBERT, PAUL K. HILLMANN.

